Re: [PATCH 2/3] KVM: x86: Save&restore interrupt shadow mask

Jan Kiszka
2010-02-17T09:07:30Z

Zachary Amsden wrote:
> On 02/16/2010 02:39 PM, Marcelo Tosatti wrote:
>> On Mon, Feb 15, 2010 at 10:45:42AM +0100, Jan Kiszka wrote:
>>
>>> The interrupt shadow created by STI or MOV-SS-like operations is part of
>>> the VCPU state and must be preserved across migration. Transfer it in
>>> the spare padding field of kvm_vcpu_events.interrupt.
>
> STI and MOV-SS interrupt shadow are both treated differently by
> hardware. Any attempt to unify them into a single field is wrong,
> especially so in a hardware virtualization context, where they are
> actually represented by different fields in the undocumented but
> nevertheless extant format that can be inferred from the hardware
> virtualization context used by specific vendors.

Someone should ask AMD why they thought differently about this while
designing SVM...

Jan

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